An electrified powertrain of a battery electric vehicle, power plant, or other torque system typically includes at least one high-voltage electric machine. The electric machine draws electrical power from a direct current (DC) power supply such as a battery pack or a fuel cell. The energized electric machine, when embodied as an electric traction motor or a motor/generator unit, can deliver motor torque to various gear sets of a transmission. A boost converter may be used in some designs to increase the battery output voltage to a level suitable for use by the electric machine.
An electric machine of the type typically employed in high-voltage torque-generating systems is typically embodied as a polyphase device, and therefore conversion of the DC output voltage of the DC device is necessary. For this reason, a power inverter module or PIM having semiconductor switches, e.g., IGBTs or MOSFETs, is electrically connected between the DC power supply and the electric machine. The semiconductor switches are automatically controlled via switching signals from a motor controller. Operation of the PIM ultimately converts the boosted DC output voltage into an AC output voltage, which is then applied to the individual phase windings of the electric machine. The energized electric machine produces motor torque suitable for driving the system or recharging the various cells of the battery pack depending on the configuration of the powertrain and operating mode.